HLA-B5-restricted auto-tumor-specific cytotoxic T cells generated in mixed lymphocyte-tumor-cell culture

T-cell-enriched lymphocyte populations derived from the malignant exudate of a patient with ovarian carcinoma were exposed to autologous tumor cells in the mixed lymphocyte-tumor-cell culture (MLTC) and propagated for 42 days. Proliferation of lymphocytes depended on exposures to autologous tumor cells and on the presence of IL-2. After 7 days, the MLTC-lymphocytes lysed K562 and the autologous tumor cells. The latter effect was not inhibited by monoclonal antibodies (MAbs) reactive with MHC class-I antigens or with CD3. After 7 restimulations, the culture was enriched in CD8+ cells (92%) and showed selective lytic activity against the autologous tumor. This function was inhibited by the alpha-class I or alpha-CD3 MAbs, and also by antibodies reactive with the HLA B locus or B5 allele products. The antibodies reactive with HLA A molecules had no such effect. It seems therefore that the function of the CTLs was restricted by HLA B5. Analysis of the TCR beta genes indicated clonal T-cell expansion in this culture. This MLTC was 1 of 21 initiated with 11 blood- and 10 tumor-derived lymphocyte (TIL) populations prepared from the malignant effusions of ovarian carcinoma patients. None of these ex-vivo lymphocytes lysed autologous tumor cells. In 17 MLTCs the lymphocytes did not proliferate, and in 3 cultures the proliferation was maintained only for 2-3 weeks. In 3 of 4 cultures auto-tumor cytotoxicity was induced.